The present disclosure relates to a lead frame, a semiconductor device, and a method for manufacturing a lead frame.
FIGS. 27A and 27B illustrate an example of a conventional lead frame used to manufacture a quad flat no-leads (QFN) semiconductor device. FIG. 27A is a plan view illustrating a portion of a lead frame including an array of multiple unit lead frames. FIG. 27B illustrates a cross-section taken along line G-G in FIG. 27A.
As illustrated in FIG. 27A, a unit lead frame 70 includes a section bar 71 having the form of a grid, four support bars 72 extending from the section bar 71, a die pad 73 supported by the four support bars 72, and a plurality of leads 74 extending, like comb teeth, from the section bar 71 toward the die pad 73. The unit lead frame 70 includes openings 75 that form the section bar 71, the support bars 72, the die pad 73, and the leads 74. As illustrated in FIG. 27B, each opening 75 is filled with an insulating resin layer 76.
FIG. 27C illustrates a cross-section of a QFN semiconductor device 80 fabricated with the unit lead frame 70. The semiconductor device 80 includes the unit lead frame 70, a semiconductor element 81 mounted on the die pad 73, bonding wires 82 that electrically connect the semiconductor element 81 and the leads 74, and an encapsulating resin portion 83 that encapsulates the semiconductor element 81, the bonding wires 82, and other components.
A method for manufacturing the semiconductor device 80 includes mounting the semiconductor element 81 onto the die pad 73 of the unit lead frame 70 (die bonding), electrically connecting the electrode terminals of the semiconductor element 81 to the corresponding leads 74 with the bonding wires 82 (wire bonding), encapsulating the semiconductor element 81, the bonding wires 82, and other components with the resin portion 83, and dividing the lead frame illustrated in FIG. 27B into individual semiconductor devices by cutting the lead frame at the cutting lines (indicated by broken lines in the drawing) with, for example, a dicing saw (dicing). The use of the lead frame including the array of the multiple unit lead frames 70 is preferable because it enables mass production of semiconductor devices 80.
The above conventional technique is described in, for example, Japanese Laid-Open Patent Publication No. 2003-309241.